Door latch



Sept. 16, 1958 F. M. NEWELL' DOOR LATCH z Sheets-Shet 1 Filed Jan. 11, 1957 u u mw E WM M F. M. NEWELL DOOR LATCH Sept. 16, 1958 2 Sheets-Sheet 2 Filed Jan. 11, 1957 m m Mm DOOR LATCH Frank M. Newell, Lowell, Mich., assignor to Newell Manufacturing Company, Lowell, Mich., a corporation of Michigan This invention relates to latches for screen and storm doors that open outwardly, and more particularly to latches that are rotated to operate them.

A well-known type of screen or storm door latch is one in which a spindle is rotatably mounted in the door and has knobs or other handles mounted on its ends for turning it. The handle at the inner end of the spindle (the end at the inner side of the door) has a radial slot, in which the inner end of a latchbolt is pivoted. The outer end of the latchbolt, which is the end next to the door, is urged out of the slot by a spring so that the latchbolt will normally engage the back of a strike on the door frame to hold the door closed. In order to lock the door shut, a locking slide is provided which can be moved vertically into engagement with the spindle to prevent the latter from being turned. An example of such a latch is shown in Patent 2,707,121. It has been found that occasionally the locking slide accidentally moves or is moved into locking position while the door is open. If the door is then allowed to close, the latchbolt will slide back across the strike into latching position, and the door will be locked shut because the spindle cannot be turned. If there is no one in the house to release the locking slide, everyone will be locked out.

It is among the objects of this invention to provide such a latch, which does not have the disadvantage just discussed, which can be locked by a key from the outside, and in which movement of the locking slide into locking position will automatically immobilize the latchbolt.

In accordance with this invention, the door latch includes a mounting member for application to the inside of an outwardly swinging door. This member has an opening through it, which registers with a passage through the door. A rotatable member extends through the aligned openings and has in its inner end a radial slot facing the door jamb. Disposed in this slot is a latchbolt, the inner end of which is pivoted to the rotatable member, on a vertical axis. The end of the latchbolt next to the door is urged out of the slot by a spring, so that it can engage the back of an adjoining strike in order to hold the door closed. The same end of the latchbolt has a portion inside the slot that projects into the mounting member. A locking slide in the mounting member is movable vertically into engagement with the rotatable member to prevent the latter from being turned when .it is desired to lock the door. The slide has a projection that is moved between the latchbolt projection and the rotatable member when the slide is moved into locking position. This prevents the outer end of the latchbolt from being swung into the slot, and therefore it the door is open it cannot be closed completely while the rotatable member is locked against rotation. This prevents accidental lockout. The latch may also be provided with means for actuating the locking slide by a key from outside.

tes Patent Patented Sept. 16, 1958 The preferred embodiment of the invention is illustrated in the accompanying drawings, in which .Fig. 1 is a horizontal section through the stile of a door, showing my latch partly broken away in section;

Fig. 2 is a view of the inner end of the latch;

Fig. 3 is a side view and section taken on the line IIIIlI of Fig. 1;

Figs. 4 and 5 are vertical sections taken on the lines IVIV and V--V, respectively, of Fig. 3;

Fig. 6 is a fragmentary horizontal section taken on the line VI-VI of Fig. 2;

Fig. 7 is an enlarged view, similar to Fig. 5, showing the latch as it appears when locked by a key;

Fig. 8 is a vertical section taken on the line VIII-VIII of Fig. 7;

Fig. 9 is a cross section of the outside knob taken on the line IX-IX of Fig. 3; and

Fig. 10 is a view similar to the preceding view, but showing the cylinder lock turned about by a key to lock the latch.

Referring to the drawings, a pair of mounting members are held securely against the opposite sides of an outwardly swinging door 1 at opposite ends of a horizontal passage 2 (Fig. 3) extending through the door near the jamb. The outside mounting member includes a hollow escutcheon 3 having an outwardly projecting hollow hub 4 around a central opening and also having internally threaded sleeves 5 extending part way through the door. A suitable handle, such as a door knob 6, has its inner end journaled in the escutcheon hub for turning a limited number of degrees in opposite directions'. Inside of the escutcheon there is the usual torsion spring (not shown) for returning the knob to the same position every time it is released after being turned. The inside escutcheon 7 may be the same shape as the outer one and its door-engaging side is closed by a plate 8 rigidly mounted in it. Screws 9 extend through the escutcheon and plate and into sleeves 5 to hold the two mounting members tightly against the door. One end of hollow hub 10 of a laterally extending handle 11 is journaled in the escutcheon hub.

Rigidly mounted in the knob and handle are the opposite ends of a spindle 12 that extends loosely through the door and mounting members for rotation therein, as

' shown in Fig. 3. The hub of the handle is provided with a radial slot 13 normally facing the door jamb or frame 14. Slidably disposed in this slot is a flat latchbolt 15, the inner end of which is connected to the handle by a vertical pivot pin 16. As shown in Fig. l, the latchbolt is swung out of the slot at an angle by means of a coil spring 17 compressed between the back of the latchbolt and the back of the slot. The distance that the outer end of the latchbolt can project from the handle can be limited in various ways, such as by a small tongue 18 projecting from the outer end of the latchbolt inside the The exposed edge slot into the adjoining escutcheon. of the outer end of the latchbolt engages the back of a strike 19 mounted on the door frame beside the latch.

The latchbolt is disengaged from the strike by turning the handle or knob to swing the latchbolt bodily up or down far enough to clear the strike. The only time that the latchbolt is pushed back into the handle is when the door is swung shut without turning the spindle. In such cases the inclined edge of the projecting latchbolt will engage the strike and be swung by it into the handle as the door closes, and then will snap out again behind the strike to hold the door shut. To permit the latchbolt to be swung into the handle the necessary distance, the spindle behind the latchbolt is provided with a radial groove 21 to receive it. A convenient way of providing such a groove is to form the spindle out of a strip of 3 metal that is bent into theshape of a channel. The open side of the channel receives part of the latchbolt when the latter is pushed into the handle.

The door can be locked by providing means which will prevent the spindle from being turned. For this purpose a locking slide 22 is slidably mounted in the inner escuteheon 7. The slide is provided with a central spindle-receiving opening 23 that is keyhole shape as shown in Figs. and 7, the circular part of the opening allowing the spindle to turn, but the rectangular part of the opening preventing rotation when the slide is moved vertically to fit that part over the spindle. See Fig. 7. The slide can be moved up and down by vertical bars 24 integral therewith extending through notches in the top and bottom of the escutcheon. The ends of these bars are bent away from the door to form pushing surfaces for the fingers.

It is a feature of this invention that the locking slide 22 is also used to prevent anyone from being locked out accidentally. It will be seen that if the locking slide is accidentally moved into locking position while the door is open it will not be possible to turn the outside knob of the latch, and yet the door as described this far could close because the latchbolt would ride over the strike. To avoid such a situation, the locking slide is provided at the side of the narrow portion of its central opening with a dog 26 that will move into the space between the spindle and the latchbolt tongue 18 (Fig. 8) when the slide is pushed into locking position, which is up as illustrated in the drawings. The dog will then prevent the latchbolt from being swung back into the handle. Consequently, if the slide is moved up into locking position while the door is open and then the door is released and attempts to swing shut, the latchbolt will not be able to slide past the strike, so that door will be unable to close far enough for the latchbolt to engage the back of the strike and lock the door. To help hold the locking slide in its two positions, it is provided with a detent 27 (Figs. 6 and 7) that can project into either of a pair of vertically spaced holes 28 (Fig. 4) in the plate 8. The slide is pressed firmly against the plate by a thin fiat spring 29 (Fig. 5) mounted in the escutcheon and having an outwardly bent central portion compressed against the slide.

In order to permit the door to be locked or unlocked from the outside, the knob 6 is provided with an axial opening through it in line with the spindle 12 secure: in its inner end. Mounted in this opening in a well-known manner is a conventional cylinder lock 31, as indicated in Figs. 3, 9 and 10, that can be turned in the knob by a key in the usual way. Also, as is customary with such locks, the key cannot be removed from the lock except when the key is vertical. The inner end of the cylinder lock is provided with an axial slot 32 that receives the flattened outer end of a rod 33 extending along the spindle in its groove 21. The rod is loose in the spindle so that it can be turned by the lock without turning the spindle. The rod extends through the door to a point adjacent locking slide 22. At that point the rod is bent so that it will extend at right angles out of the spindle, and the tip 34 of this projecting portion is again bent at a right angle so that it will project into a vertical slot 35 in the slide. In other words, the rod has the general form of a bell crank. To permit the tip of. the rod to move the slide up and down when the rod is turned, the inner plate 8 of escutcheon 7 is provided with a large flaring notch 36, as shown in Fig. 4. Also, the top and bottom walls of spindle 12 are provided with notches 37.

It will be seen that when the cylinder lock is turned about 90 by a key, the rod 33 will move the slide up into locking position as shown in Figs. 7, 8 and 10. When the key is turned back to vertical position to withdraw'it from the lock, it will make no difference whether the rod tip 34 stays up or drops back. When the lock 4 is turned by the key in the opposite direction, the rod will move the slide back down and thereby unlock the door. While the door is unlocked, the knob or handle can be turned in a direction to swing the latchbolt down away from the strike without interference from the rod, because its tip can move up and down in slide slot 35. However, special provision must be made to permit the spindle to be turned in the opposite direction without the rod turning with it and attempting to raise the slide and lock the spindle at the same time it is being turned, which would jamb the latch. Accordingly, the slot in the cylinder lock is shaped so that it flares out in width from its center toward each end. With this arrangement, the spindle and lock can be turned about 45 to unlatch the door, but the rod will remain stationary and not actuate the locking slide. Consequently, this latch can be turned in either direction from inside or outside, and can be locked and unlocked from the inside or outside. There is no danger of the occupants of the house being locked out accidentally, because the latchbolt cannot swing as long as the locking slide is in locking position.

According to the provisions of the patent statutes, I have explained the principle of my invention and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

1. A door latch comprising a mounting member adapted to be applied to the inside of an outwardly swinging door and having an opening therethrough, a rotatable spindle extending through said opening, a handle rigidly mounted on the inner end of the spindle and having a horizontal radial slot, a latchbolt disposed in said slot for rotation with the spindle, means pivoting the inner end of the latchbolt to the handle on a vertical axis, a spring urging the outer end of the latchbolt out of said slot, said outer end being swingable back into the slot and having a tongue projecting into said mounting memher, and a locking slide mounted in said member and movable vertically into engagement with the spindle to prevent the spindle from being turned by the handle, the slide having a dog that is moved between said tongue and spindle when the slide is moved into spindle-engaging position, whereby to prevent the latchbolt from being swung into the handle slot while the spindle is locked.

2. A door latch comprising a mounting member adapted to be applied to the inside of an outwardly swinging door and having an opening therethrough, a rotatable spindle extending through said opening and provided with a longitudinal groove facing laterally, a handle rigidly mounted on the inner end of the spindle and having a radial slot extending along said groove, a latchbolt disposed in said slot for rotation with the spindle, means pivoting the inner end of the latchbolt to the handle on a vertical axis, a spring urging the outer end of the latchbolt out of said slot, said outer end being swingable back into the spindle groove and having a tongue projecting into said mounting member, a locking slide mounted in said member and movable vertically'into engagement with the spindle to prevent the spindle from being turned by the handle, the slide having a dog that is moved between said tongue and spindle when the slide is moved into spindle-engaging position, whereby to prevent the latchbolt from being swung into the handle slot and spindle groove while the spindle is locked, a handle rigidly mounted on the outer end of the spindle and provided with an opening therethrough in line with the spindle, a cylinder lock mounted in said opening and having an axial slot in its inner end, said slide being provided with a slot extending vertically beside the spindle, and a rod loosely disposed in said spindle groove and having a bell crank end projecting laterally out of the spindle and into said slide slot, the opposite end of the rod being disposed in said cylinder lock slot for turning by the lock to cause the rod to move the locking slide up and down.

3. A door latch according to claim 2, in which said cylinder lock slot flares out in width from its center toward each end, whereby the cylinder lock can be rotated a few degrees in either direction Without turning said rod.

4. A door latch according to claim 2, in which the upper and lower walls of said spindle groove are provided with notches that receive the laterally projecting portion of said rod when the rod and spindle are turned relative to each other.

5. A door latch comprising a mounting member adapted to be applied to the inside of an outwardly swinging door and having an opening therethrough, a rotatable spindle extending through said opening and provided with a longitudinal groove facing laterally, a handle rigidly mounted on the inner end of the spindle and having a radial slot extending along said groove, 2. latchbolt disposed in said slot for rotation with the spindle, means pivoting the inner end of the latchbolt to the handle on a vertical axis, a spring urging the outer end of the latchbolt out of said slot, a locking slide mounted in said member and movable vertically into engagement with the spindle to prevent the spindle from being turned, a handle rigidly mounted on the outer end of the spindle and provided with an opening therethrough in line with the spindle, a cylinder lock mounted in said opening and having an axial slot in its inner end, said axial slot flaring out in width from its center toward each end, said slide being provided with a slot extending vertically beside the spindle, and a rod rotatably disposed in said spindle groove and having a crank end projecting laterally out of the spindle and into said side slot, the opposite end of the rod being disposed in said cylinder lock slot and rockable back and forth between the flaring sides of that slot, whereby the rod can be turned in the spindle by the lock, and the upper and lower walls of said spindle groove being provided with notches that receive the laterally projecting portion of the rod when the rod and spindle are turned relative to each other.

6. A door latch comprhing a mounting member adapted to be applied to the inside of an outwardly swinging door and having an opening tllerethrough, a rotatable spindle extending through said opening and provided with a longitudinal groove facing laterally, a handle rigidly mounted on the inner end of the spindle and having a radial slot extending along said groove, a latchbolt disposed in said slot for rotation with the spindle, means pivoting one end of the latchbolt to the handle on a vertical axis, a spring urging the opposite end of the latchbolt forward out of said slot, a locking slide mounted in said mounting member and movable vertically into engagement with the spindle to prevent the spindle from being turned by the handle, the slide having a projection that is moved vertically into a position directly behind said latchbolt when the slide is moved into spindle-engaging position, whereby to prevent the latchbolt from being swung into the handle slot and spindle groove while the spindle is looked, a handle rigidly mounted on the outer end of the spindle and provided with an opening therethrough in line with the spindle, a cylinder lock mounted in said opening and having an axial slot in its inner end, said slide being provided with a slot extending vertically beside the spindle, and a rod loosely disposed in said spindle groove and having a bell crank end projecting laterally out of the spindle and into said slide slot, the opposite end of the rod being disposed in said cylinder lock slot for turning by the lock to cause the rod to move the locking slide up and down.

References Cited in the file of this patent UNITED STATES PATENTS 2,651,934 Chesler Sept. 15, 1953 2,700,566 Wartian Jan. 25, 1955 2,707,121 Behnke Apr. 26, 1955 2,726,533 Quinn Dec. 13, 1955 2,733,089 Grevengoed Jan. 31, 1956 

